Cu2O is used as precursors for solar energy conversion, magnetic storage medium, catalyst, gas sensor, and copper wire formation, and there are active studies related to composition of particles in a nano or micro size level.
As well known in the art, properties of particles are greatly changed according to their size. For example, ultrafine particles in a nano size level have a lower welding point than bulk particles, and activation of the ultrafine particles is maximized due to the increase of a surface area. However, the ultrafine particles have bad workability, so they are not easily handled. Thus, there is a demand for Cu2O particles that may ensure excellent workability while exhibiting their inherent properties sufficiently.
[Nano Lett. 2003, 3, 231.] discloses a preparation method of Cu2O particles with a size of 200 to 450 nm. The Cu2O particles are formed as a mixture of simple Cu2O particles with a low density, which have a hollow tube shape, so they may not easily satisfy the inherent properties and workability of ultrafine particles.
In addition, Korean Laid-open Patent Publication No. 10-2005-84099 discloses a method for preparing Cu2O particles by reducing Cu2O precursors using a hydrazine-based reducing agent. However, if such a strong reducing agent is used to prepare Cu2O particles, the size of generated Cu2O particles is rapidly increased due to rapid reduction reaction, so the Cu2O assembly particles have irregular shapes, and the particle sizes also become more irregular.
Meanwhile, Japanese Laid-open Patent Publication No. 2006-96655 discloses a method for preparing Cu2O particles by reducing copper sulfate using a weak reducing agent. The Cu2O particles prepared using copper sulfate as a precursor are made as a mixture of simple Cu2O ultrafine particles.